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green trillium, Ozark green trillium, Ozark trillium, tapertip wakerobin

dwarf trillium, dwarf wakerobin, least trillium, little trillium

Rhizomes

horizontal, brownish, short, thick, praemorse, not brittle.

horizontal, branching, thin.

Scapes

1–3, round in cross section, 2–5 dm, ± stout, glabrous to scabrous.

1–2, round in cross section, 0.7–2 dm, slender, becoming taller and more robust after flowering, glabrous.

Bracts

touching ground in early anthesis or not at all, sessile;

blade dark green, obscurely marked with few–many darker blotches (very rarely unmottled), mottling becoming obscure with age, few or no stomates adaxially, ovate-elliptic to broadly so, 8.5–14 × 6.8–9 cm, apex acuminate.

very short-petiolate, subsessile or sessile;

blade dark green with maroon undertones when young, not mottled, 3–5 major veins from base, oblong to lanceolate-obtuse, 2.5–8+ × 1–3 cm, not glossy, apex obtuse.

Flower

erect, odor, if present, spicy or musty;

sepals displayed above bracts, widely spreading, green or variously purple marked, lanceolate, 38–60 × 5–12 mm, margins entire, apex acute;

petals long-lasting, erect, ± connivent, ± concealing stamens and ovary, purplish black on claw, greenish to yellow-green distally, sometimes all dark purple, occasionally slightly twisted, linear to narrowly spatulate, 4–8 × 0.8–1.2 cm, thick-textured, base slightly thickened and clawed, margins entire, apex rounded, lacking nipple;

stamens erect, connivent (clustered together, leaning upon each other), 16–25 mm;

filaments olive or purplish brown, 2.5–5 mm, very slender, widened basally;

anthers erect, straight or slightly incurved, olive-brown, 13–20 mm, ± slender, dehiscence latrorse;

connectives brownish, barely extending beyond anther sacs;

ovary pale greenish white basally, purplish distally, ovoid, 6-angled, 5.5–10 mm;

stigmas erect, divergent-recurved, distinct, purplish abaxially, sessile, almost linear, 6–10 mm, ± equaling ovary, ± not fleshy, very slightly widened basally.

above bracts, erect, odorless to faintly sweet, pedicellate or sessile;

sepals conspicuous, spreading to same plane as petals, dark green with maroon undertones when young, oblong-lanceolate, 15–30 × 5–10 mm, margins entire, apex obtuse to strongly rounded;

petals of short duration, spreading-ascending, exposing stamens and ovary, weakly recurved in distal 1/2, white, aging to deep rosy pink abaxially, veins not engraved but major petal veins clearly visible, oblong to narrowly lanceolate, 1.5–3 × 0.5–1.5 cm, thin-textured, widest above base, margins strongly undulate, quite variable in petal width and degree of undulation between individuals and populations, apex obtuse to weakly acute;

stamens erect-spreading, 8–10 mm;

filaments pinkish purple to white, ± equaling or slightly shorter than anthers, slender;

anthers ± straight, pale lavender or yellow, 3–8(–10) mm, thicker than filaments, dehiscence introrse;

connectives not extended beyond anther sacs;

ovary conspicuous, white, ovoid, obscurely 6-angled, 2.5–8 mm, attachment narrower than ovary;

stigmas confluent with style, greenish white to white, distally 3-lobed, lobes linear (threadlike), long-spreading, 3–12 mm, uniformly thin and threadlike;

pedicel stiffly erect to leaning, 0.5–2 cm, or absent to much reduced.

Fruits

dark purplish green or green, odor unreported, ovoid, obscurely angled, with remains of persistent stigma, 0.7–1.5 cm, pulpy, not juicy at time of separation from receptacle.

white or pale greenish, ovate, 1–1.5 cm, pulpy, moist but not juicy.

2n

= 10.

Trillium viridescens

Trillium pusillum

Phenology Flowering spring (early Apr–mid May).
Habitat Deciduous forests, usually quite rich, on banks, bluffs, talus slopes, floodplain alluvium, with cane (Arundinaria) or on sloping banks just above normal flood levels in heavy, clayey soils, with common spring ephemerals
Elevation 100–400 m (300–1300 ft)
Distribution
from FNA
AR; KS; MO; OK; TX
[WildflowerSearch map]
[BONAP county map]
from USDA
sc United States; se United States
[WildflowerSearch map]
[BONAP county map]
Discussion

Of conservation concern.

J. D. Freeman (1975) considered that Trillium viridescens intergrades with T. gracile in northeastern Texas and stated that these putative intergrades produce purple petals, but purple-petaled forms also occur in Arkansas, far from the influence of T. gracile.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Varieties 2 (2 in the flora).

Trillium pusillum comprises widely disjunct, regional populations, each varying somewhat from the others and variable within itself as well. Some of these populations have been named as varieties or separate species. In the wild, the plants that have been recognized as var. ozarkanum generally grow taller than others and are said to have bracts with five major veins instead of three. Plants attributed to var. texanum, on the other hand, are generally smaller in all parts, with narrower petals, and often revert to a single bract when not flowering. Only var. virginianum is easily distinguished at sight by its “sessile” flower. This variety has received extensive study. P. R. Cabe (1995), in a morphological study including statistical analysis, found variation within and between populations. He felt that his results were inconclusive, and also that some of the variation might be environmentally induced. The variation that he found did not correlate with a geographic pattern, and he suggested treating all Virginia populations as var. virginianum, or simply T. pusillum. In a later study, P. R. Cabe and C. R. Werth (1995), using isozyme evidence, obtained like results, and suggested treating all Virginia populations as a single variety pending further investigation. Until there has been such study, of the Virginia plants as well as the rest of the T. pusillum complex, I choose to retain the fairly distinctive and more or less traditionally known var. virginianum, and include all other populations in a broadly circumscribed var. pusillum.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Key
1. Flower pedicillate; pedicel usually 0.5–2 cm.
var. pusillum
1. Flower sessile or subsessile; pedicel, if present, 0.1–0.3 cm
var. virginianum
Source FNA vol. 26, p. 117. FNA vol. 26, p. 101.
Parent taxa Liliaceae > Trillium > subg. Phyllantherum Liliaceae > Trillium > subg. Trillium
Sibling taxa
T. albidum, T. angustipetalum, T. catesbaei, T. cernuum, T. chloropetalum, T. cuneatum, T. decipiens, T. decumbens, T. discolor, T. erectum, T. flexipes, T. foetidissimum, T. gracile, T. grandiflorum, T. kurabayashii, T. lancifolium, T. ludovicianum, T. luteum, T. maculatum, T. nivale, T. ovatum, T. parviflorum, T. persistens, T. petiolatum, T. pusillum, T. recurvatum, T. reliquum, T. rivale, T. rugelii, T. sessile, T. simile, T. stamineum, T. sulcatum, T. underwoodii, T. undulatum, T. vaseyi, T. viride
T. albidum, T. angustipetalum, T. catesbaei, T. cernuum, T. chloropetalum, T. cuneatum, T. decipiens, T. decumbens, T. discolor, T. erectum, T. flexipes, T. foetidissimum, T. gracile, T. grandiflorum, T. kurabayashii, T. lancifolium, T. ludovicianum, T. luteum, T. maculatum, T. nivale, T. ovatum, T. parviflorum, T. persistens, T. petiolatum, T. recurvatum, T. reliquum, T. rivale, T. rugelii, T. sessile, T. simile, T. stamineum, T. sulcatum, T. underwoodii, T. undulatum, T. vaseyi, T. viride, T. viridescens
Subordinate taxa
T. pusillum var. pusillum, T. pusillum var. virginianum
Synonyms T. pumilum
Name authority Nuttall: Trans. Amer. Philos. Soc., n. s. 5: 155. (1837) Michaux: Fl. Bor.-Amer. 1: 215. (1803)
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